Switchgear assemblies and switchboards and panel boards are general terms which cover metal enclosures, housing switching and interrupting devices such as fuses and circuit breakers, along with associated control, instrumentation and metering devices. Such assemblies typically include associated bus bars, interconnections and supporting structures used for the distribution of electrical power. Low voltage switchgear and switchboards operate at voltages of up to 600 volts and with continuous currents up to 5000 amps or higher. Such devices are also designed to withstand short circuit currents ranging up to 200,000 amps (3 phase RMS symmetrical).
Typical switchgear equipment is composed of a lineup of several metal and closed sections. Each section may have several circuit breakers stacked one above the other vertically in the front of the section with each breaker being enclosed in its own metal compartment. Each section has a vertical or section bus which supplies current to the breakers within the section by short horizontal branch busses, also referred to as run-in busses. The vertical bus bars in each section are supplied with current by a horizontal main bus bar that runs through the lineup of metal enclosed sections. The vertical bus bars may be configured as separate individual sections that require isolation from each other vertically as well as horizontally. A typical arrangement includes bus bars for each electrical phase of a multi-phase system which may include three power phases and a neutral.
In multi-phase systems, it is desirable to isolate the bus bars of each phase from each other and the other components in the enclosure. Isolation is beneficial to minimize hazards to personnel and to reduce arc fault hazards. Since configuration of switchboard enclosures and equipment vary from application and installation, a modular standard insulation system is easier to configure and install.
Thus there is a need for a modular insulation system for an electrical equipment enclosure having multi-phase vertical and horizontal bus bars. There is a further need to have an isolation system that can be easily configured, maintained, and installed without special tools and with a minimum of tools.